Piping systems exist to facilitate the flow of fluids (e.g., liquid, gas (such as air) or plasma). For example, homes, schools, medical facilities, commercial buildings and other occupied structures generally require integrated piping systems so that water and/or other fluids can be circulated for a variety of uses. Liquids and/or gases such as cold and hot water, breathable air, glycol, compressed air, inert gases, cleaning chemicals, waste water, plant cooling water and paint and coatings are just some examples of the types of fluids and gases that can be deployed through piping systems. Tubing and piping types can include, for example, copper, stainless steel, CPVC (chlorinated polyvinyl chloride) and PEX (cross-linked polyethylene). For purposes of the present disclosure, the term “tube”, “pipe”, “piping” or “piping element” will be understood to encompass one or more pipes, tubes, piping elements and/or tubing elements.
Piping connections are necessary to join various pieces of pipe and must be versatile in order to adapt to changes of pipe direction required in particular piping system implementations. For example, fittings and valves may be employed at the ends of open pieces of pipe that enable two pieces of pipe to fit together in a particular configuration. Among fitting types there are elbows, “tees”, couplings adapted for various purposes such as pipe size changes, ends, ball valves, stop valves, and partial angle connectors, for example.
In the past, pipe elements have been traditionally connected by welding and/or soldering them together using a torch. Soldering pipe fittings can be time-consuming, unsafe, and labor intensive. Soldering also requires employing numerous materials, such as copper pipes and fittings, emery cloths or pipe-cleaning brushes, flux, silver solder, a soldering torch and striker, a tubing cutter and safety glasses, for example. The process for soldering pipes can proceed by first preparing the pipe to be soldered, as the copper surface must be clean in order to form a good joint. The end of the pipe can be cleaned on the outside with emery cloth or a specially made wire brush. The inside of the fitting must be cleaned as well. Next, flux (a type of paste) can be applied to remove oxides and draw molten solder into the joint where the surfaces will be joined. The brush can be used to coat the inside of the fitting and the outside of the pipe with the flux. Next, the two pipes are pushed together firmly into place so that they “bottom out”—i.e., meet flush inside the fitting. The tip of the solder can be bent to the size of the pipe in order to avoid over-soldering. With the pipes and fitting in place, the torch is then ignited with the striker or by an auto-strike mechanism to initiate soldering. After heating for a few moments, if the copper surface is hot enough such that it melts when touched by the end of the solder, the solder can then be applied to the joint seam so that it runs around the joint and bonds the pipe and fitting together.
In recent years, push-fit technology has been employed with piping systems to reduce the dangers and time involved in soldering joints. Push-fit methods require minimal knowledge of pipe fittings and involve far fewer materials than soldering. For example, one may only need the pipes, quick-connect fittings, a chamfer/de-burring tool and tubing cutter in order to connect pipes using push-fit technology.
The steps involved in connecting piping systems using push-fit technology can be outlined as follows. First, the pipe is cut to the appropriate length and the end of the pipe is cleaned with the de-burring tool. Then the pipe and fitting are pushed together for connection. The fitting is provided with a fastening ring (also called a collet, grip ring or grab ring) having teeth that grip the pipe as it is inserted. The fastening ring device is employed to provide opposing energy, preventing the device from disconnection while creating a positive seal.
Accordingly, no wrenches, clamping, gluing or soldering is involved. Push-fit and/or quick-connect technology for piping systems can be obtained, for example, through Quick Fitting, Inc. of East Providence, R.I., USA, suppliers of the CoPro® line of push fittings and related products. Also, such technology is described, for example, in U.S. Pat. Nos. 7,862,089, 8,205,915, 8,210,576, 8,398,122, and 8,480,134, the disclosures of which are incorporated herein by reference in their entireties.
In past pipe coupling technology, the fastening ring is inserted into the fitting body along with a plastic grip ring support that typically fails under extensive tensile testing. Further, the coupling must then be either coin rolled, glued or receive a threaded cap member to retain the fastening ring inside the fitting body. In addition to the added steps for the manufacture and assembly of the coupling, the strength of the plumbing joint is determined by the retaining cap member. The additional steps and components add significant labor and manufacturing costs to the final product cost and reduce the overall production capability due to the extensive time required for proper assembly.
In addition to the above, when using a threaded retaining cap method, the process of cutting threads into the fitting body and the retaining cap elevates the cost of machining the fitting components. Further, the threaded end cap method requires mechanical assembly as well as the added cost and application of a thread sealant to the threads. In prior efforts that employ a coined retaining cap method, the process of coining the fitting body as the retaining cap significantly increases the cost of final assembly of the fitting. Additionally, the coining process permanently encapsulates the fastening ring inside the fitting, whereby the fastening ring cannot be removed without complete destruction of the ring and fitting.
Along with additional assembly steps and increased manufacturing costs, past pipe fittings and connection methods do not allow repair for various reasons. In some cases, this is because they are factory sealed, for example. In other cases, it is because the separation of the fitting from the pipe can damage or induce wear on the parts. For example, some push-to-connect fittings provide permanently fixed demounting rings for removing the fittings. The demounting rings can be depressed axially to lift the fastening ring teeth off of the surface of the inserted pipe, such that the pipe can then be withdrawn. This arrangement, however, can subject the fittings to tampering and shorter life. In addition, while fastening ring devices work effectively as an opposing retaining member, their functionality makes them nearly impossible to dismount, remove or detach for re-use. The fastening rings are thus permanently affixed unless they are cut and removed, which then destroys the fastening ring.
Whether connected by traditional soldering methods or with push-fit methods, practical applications invariably require the replacement of fittings and valves, and do not allow re-use of the fittings or valves in instances where only a small internal component needs to be repaired or replaced.